Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 65 for “"Comminution"”.
-
The fracture and autogenous comminution of quartzite
Comminution is the process which aims at increasing the surface area and the resultant liberation of a particular constituent from the mass of a solid. The autogenous mill uses tumbling to effect comminution, but instead of special milling bodies being added, pebbles of the material to be …
-
The release of nitrogen and carbohydrate from herbage during comminution
… variation between forages in N release during comminution of herbage, explore the characteristics of herbage that influence N release, and consider implications for N excretion. Two laboratory based experiments were conducted to examine the release of N during mechanical maceration of herbage, …
-
Segregation control of binary size particles in a comminution device
Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1991
-
Particle breakage and material transport in the design of high-efficiency comminution device
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1991.
-
Molecular Dynamics Simulation of Forsterite and Magnesite Mechanical Properties: Effect of Carbonation on Comminution Energy
… in hardness reduction of rock and subsequently comminution energy during the crushing and processing of the ore. We investigated how these materials respond to different physical conditions, such as temperature and strain rate, to understand their behavior under stress. By examining the …
-
Dielectric Properties of Minerals and Ores and the Application of Microwaves for Assisted Comminution and Ore Sorting
… research gaps in the field of microwave-assisted comminution and ore sorting and found that developments have been limited by complexities associated with scaling up from bench- to pilot-scale. Dielectric properties were measured on key sulphide and silicate minerals and select ores at various …
-
Using discrete element modelling (DEM) and breakage experiments to model the comminution action in a tumbling mill
… of the model to predict the product of the comminution process. In order to test the proposed tumbling mill model, DEM simulations of a 1.695m diameter pilot SAG mill using charge based on actual operation data were performed and analysed. Results from the DEM simulation and Drop Weight …
-
Mitigating material supply risks: evaluation of abrasion specific comminution for commercial recovery of indium from waste liquid crystal displays
Indium is a valuable commodity of great importance to the adoption of low carbon energy technologies including solar and nuclear. Many geopolitical entities; however, view the stability of indium’s supply chain with concern. While the United States currently imports 100% of its indium from other …
-
Adaptable Design Improvements For Electromagnetic Shock Wave Lithotripters And Techniques For Controlling Cavitation
… was characterized and tested for in vitro stone comminution efficiency at a variety of field positions and doses using phantom kidney stones of variable hardness, and in different fluid mediums to isolate the contribution of cavitation. Through parametric analysis of the acoustic field …
-
The rational design of drug crystals to facilitate particle size reduction. Investigation of crystallisation conditions and crystal properties to enable optimised particle processing and comminution.
… number of cracks showed a greater propensity for comminution. Salbutamol sulphate with a high degree of crystal dislocations however gave highly energetic powders, with reduced degree of crystallinity owing to the role dislocations play in facilitating plastic deformation, minimising fragmentation …
-
Investigating the products from different modes of particle breakage testing
The development of realistic comminution models is dependent on the accuracy with which ore breakage can be predicted. This hinges on our understanding of the basic concepts of breakage and the different modes in which it manifests in the comminution environment. Three distinctly different modes of …
-
Effect of VRM on a polymetallic sulfide ore and the flotation response as compared to conventional wet and dry rod milling
Comminution is an energy intensive, size reduction and mineral dressing process which consumes up to 50% of concentrator energy consumption. Conventional methods use mainly a combination of crushers and tumbling mills in comminution circuits. Energy consumption in these circuits has been found to …
-
PLASMA SPECTROCHEMICAL ANALYSIS OF SLURRIES
… 5 µm, preferably below 3 µm for refractories. Comminution techniques were used to reduce samples to this size range; the comminution time depended upon sample hardness. Suitable dispersants were identified. Laser diffraction measurements showed the modification of aerosol distributions, for …
-
The Influence of Design and Operational Parameters on Microniser Performance
… to establish the optimum features for maximum comminution efficiency. Using the optimum design the main operational parameters were studied. Fluid injection velocity and pressure of the fluid medium were varied and the influence of these and of the solids to fluid ratio on the comminution …
-
Fracture Toughness Based Models for the Prediction of Power Consumption, Product Size, and Capacity of Jaw Crushers
… that comparison of fracture toughness, specific comminution energy, and breakage distribution could be performed. The results indicate that the specific comminution energy required to reduce a rock particle to a given size increases with fracture toughness. The breakage distribution has also been …
-
Aplicação de modelos de quebra de partículas do ambiente de simulação do método dos elementos discretos no estudo de microprocessos de cominuição
In this work one of the comminution microprocesses were studied using three particle breakage models within the DEM simulation environment: The Bonded Particle Model – BPM, the Fast Breakage Model - FBM, and the Particle Replacement Model – PRM. Such models were calibrated on the basis of the …
-
The effect of microwave radiation on mineral processing
… in the extraction process may be attributed to comminution. Microwave pre-treatment has been suggested as a means to decrease the energy requirements. A variety of mineral ores have been investigated and the effects of microwave radiation quantified in terms of the mineralogy, changes in the …
-
Performance of the vertical roller mill in a mineral processing application when coupled with internal and external classifiers
Comminution is applied in all mineral processing plants where mineral liberation is needed for separation and concentration of valuable minerals. The process is energy intensive and is predominantly carried out in tumbling mills which are known to be highly inefficient. Comminution technologies …
-
Solar energy in the minerals processing industry: identifying the first opportunities
… likely to benefit from the use of solar energy. Comminution, hot leaching processes and electrowinning circuits are shown to be the most energy intensive areas. Comminution requires high voltage AC power which can be supplied by the solar thermal (ST) technology which converts solar heat to steam …
-
Resistance of a granular medium to normal impact of a rigid projectile
… to be related to the energy necessary for comminution of the sand particles. The static coefficients, C and D can be found from the strength properties of the soil (c, φ and y) or from a static penetration test. A linear relationship was found between the static resistance, C , and the …
Page 1 of 4